Peucat, J-JMascarenhas, J FBarbosa, Johildo F. S.de Souza, S LMarinho, M MFanning, ChristopherLeite, C M M2015-12-130895-9811http://hdl.handle.net/1885/94244Felsic metavolcanics associated with supracrustal rocks provide U-Pb zircon and Sm-Nd TDM ages of approximately 3.3 Ga, which establish an Archean age of the Mundo Novo greenstone belt. A granodioritic gneiss from the Mairi complex, located on the eastern boundary of the Mundo Novo greenstone belt, exhibits a zircon evaporation minimum age of 3.04 Ga and a Nd model age of 3.2 Ga. These results constrain the occurrence of at least three major geological units in this area: the Archean Mundo Novo greenstone belt, the Archean Mairi gneisses, and the adjoining Paleoproterozoic (<2.1 Ga) Jacobina sedimentary basin. The Jacobina basin follows the same trend as the Archean structure, extending southward to the Contendas-Mirante belt, in which a similar Archean-Paleoproterozoic association appears. We postulate that during the Paleoproterozoic in the eastern margin of the Gavião block, these Archean greenstone belts constituted a zone of weakness along which a late-stage orogenic sedimentary basin developed.Keywords: Archean; geochronology; greenstone belt; metavolcanic rock; Brazil Metavolcanic rock; Mundo Novo greenstone belt; Zircon age200210.1016/S0895-9811(02)00044-52015-12-12